MEXICO CITY -- As money and migration yank Mexico toward the north, President Vicente Fox was in the south of the hemisphere on Thursday, seeking a little balance.

Mexico boasts of being Latin America's richest nation and its top exporter. Yet those accomplishments have come at the cost of increasingly dramatic dependence on its wealthier northern neighbor.

Eighty-nine percent of Mexico's legal exports go to the United States. Ten percent of its population lives there. The largest share of its income from tourism and foreign remittance - and the huge market in illegal drugs, for that matter - comes from the United States.

Less than one third of one percent of Mexican exports go to the giant of South America's markets, Brazil.

So in purely economic terms, it might be generous to say that Fox's talks Thursday with South America's Mercosur trading bloc, led by Brazil, mean little in the short run.

Mercosur itself "is a failed customs union," said Robin Rosenberg, a trade expert at the University of Miami. "It's had more major trade disputes than countries that don't even have trade agreements."

Only days before Mercosur met to celebrate its unity this week, Argentina announced trade restrictions on Brazilian electronics.

But Mercosur means a lot to Mexico's profoundly rooted sense of itself as a Latin American nation, to its ability to negotiate with richer countries and to its lost leadership as a leader in Latin America.

It's an identity reinforced in many ways, from a shared history and literature to a common interest in this week's Copa America soccer tournament in Peru that has drawn vastly more news coverage here than Fox's trip.

"Mexico needs desperately to show its Latin American counterparts that it is not enslaved to its North American trading partners," Rosenberg said.

He said that Mexico - which was seen as a beacon of independence and a haven for refugees in Latin America during much of the 1970s and 1980s - had largely surrendered the role of regional leader to Brazil when it entered the North American Free Trade Agreement with Canada and the United States in 1994.

Mexico wants to regain some of that influence - and wants even more to lessen its dependence on the ups and downs of the American economy and the uncertainties of U.S. politics.

One way is to reinforce Mexico's historically and emotionally strong ties with Latin America and build alliances that have more strength in dealings with outside forces such as the United States.

"It's clear that if we are united politically, our weight as a region internationally will be much greater," said Miguel Hakim, Mexico's deputy foreign secretary for Lain America. "That is what Mexico is seeking in its connection with Mercosur."

Mexico and Brazil are united in their call for a new permanent member of the U.N. Security Council from Latin America, even if they have been rivals in competing for the possible position.